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PEP8 radio/util/codecs.py

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Fix white space
This commit is contained in:
Sean Vig 2015-10-08 23:39:54 -05:00
parent 054952edcb
commit be154140b3
1 changed files with 20 additions and 15 deletions
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35
radio/util/codecs.py
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@ -2,52 +2,57 @@
from __future__ import print_function from __future__ import print_function
SIGN_BIT = (0x80) # Sign bit for a A-law byte. SIGN_BIT = (0x80) # Sign bit for a A-law byte.
QUANT_MASK = (0xf) # Quantization field mask. QUANT_MASK = (0xf) # Quantization field mask.
SEG_SHIFT = (4) # Left shift for segment number. SEG_SHIFT = (4) # Left shift for segment number.
SEG_MASK = (0x70) # Segment field mask. SEG_MASK = (0x70) # Segment field mask.
BIAS = (0x84) # Bias for linear code. BIAS = (0x84) # Bias for linear code.
def alaw2linear(a_val): def alaw2linear(a_val):
a_val ^= 0x55 a_val ^= 0x55
t = a_val & QUANT_MASK t = a_val & QUANT_MASK
seg = (a_val & SEG_MASK) >> SEG_SHIFT seg = (a_val & SEG_MASK) >> SEG_SHIFT
if (seg): if (seg):
t = (t + t + 1 + 32) << (seg + 2) t = (t + t + 1 + 32) << (seg + 2)
else: else:
t = (t + t + 1 ) << 3 t = (t + t + 1) << 3
if a_val & SIGN_BIT: if a_val & SIGN_BIT:
return t return t
else: else:
return -t return -t
def ulaw2linear(u_val):
def ulaw2linear(u_val):
# Complement to obtain normal u-law value. # Complement to obtain normal u-law value.
u_val = ~u_val u_val = ~u_val
# Extract and bias the quantization bits. Then # Extract and bias the quantization bits. Then
# shift up by the segment number and subtract out the bias. # shift up by the segment number and subtract out the bias.
t = ((u_val & QUANT_MASK) << 3) + BIAS t = ((u_val & QUANT_MASK) << 3) + BIAS
t <<= (u_val & SEG_MASK) >> SEG_SHIFT t <<= (u_val & SEG_MASK) >> SEG_SHIFT
if u_val & SIGN_BIT: if u_val & SIGN_BIT:
return (BIAS - t) return (BIAS - t)
else: else:
return (t - BIAS) return (t - BIAS)
def pcmTable(fn): def pcmTable(fn):
result = [] result = []
for i in range(256): for i in range(256):
result.append(fn(i)) result.append(fn(i))
return result return result
def tableToString(name, table):
result = 'const int16_t ' + name + '[256] = { ' def tableToString(name, table):
result += ', '.join([str(i) for i in table]) result = 'const int16_t ' + name + '[256] = { '
result += ', '.join(str(i) for i in table)
result += ' };' result += ' };'
return result return result
print(tableToString('alawTable', pcmTable(alaw2linear))) print(tableToString('alawTable', pcmTable(alaw2linear)))
print(tableToString('ulawTable', pcmTable(ulaw2linear))) print(tableToString('ulawTable', pcmTable(ulaw2linear)))